On Fri, Aug 16, 2013 at 01:35:22AM +0000, AntC wrote:
There's an annoying inconsistency:
(CustId 47, CustName "Fred", Gender Male) -- threeple (CustId 47, CustName "Fred) -- twople -- (CustId 47) -- oneple not! () -- nople
(That is, it's annoying if you're trying to make typeclass instances for extensible/contractable tuples. Yes, I know I could use HLists.)
I'm not happy with either approach I've tried:
data Oneple a = Oneple a -- (or newtype) (Oneple $ CustId 47) -- too verbose
type Oneple a = [a] [CustId 47] -- at least looks bracket-y
What do you do?
This is what the OneTuple package is for: http://hackage.haskell.org/package/OneTuple -Brent